Massive Star Formation and Accretion Processes

Massive star formation (above 8 M⊙) unfolds within dense molecular clouds, where gravitational collapse and angular-momentum conservation give rise to rotating protostellar discs and bipolar outflows. Unlike their low-mass counterparts, high-mass young stellar objects evolve rapidly and often within clustered environments, producing complex interactions among accretion flows, radiative feedback and core fragmentation. Keplerian-like rotation has now been observed in several massive discs, confirming that disc-mediated accretion remains a dominant growth mechanism even at high masses. Concurrently, powerful jets and wide-angle winds remove angular momentum and regulate infall. Magnetic fields and radiation pressure shape the accretion geometry, sometimes triggering episodic accretion bursts. Cluster dynamics, including competitive accretion and dynamical encounters, further influence mass assembly and multiplicity. Recent advances in millimetre interferometry and infrared spectroscopy are closing the gap between theory and observation, illuminating the initial conditions, fragmentation pathways and ultimate outcomes of massive star birth.

Research from Nature Portfolio

Recent studies have identified rotating disc structures in extragalactic and Galactic settings, demonstrating the universality of disc-mediated accretion. Observations of a massive young star in a low-metallicity galaxy reveal a Keplerian toroid feeding an inner accretion disc that is optically revealed due to reduced dust content, extending canonical models beyond our own Galaxy. High-resolution imaging of a dense protocluster has uncovered quintuple, quadruple and triple protostellar systems forming simultaneously within 0.1 pc, with little evidence for large Keplerian discs. These results indicate that core fragmentation, rather than disc fragmentation, plays a crucial role in establishing multiplicity in high-mass star clusters, while accretion proceeds through more compact, possibly transient disc structures.

Massive Star Formation and Accretion Processes publication trend

The graph below shows the total number of articles in massive star formation and accretion processes across all publications each year (not limited to Nature Index journals).

Technical terms

Keplerian disk: A rotating disc in which orbital velocity decreases with radius following Kepler’s laws around a central mass.

Massive Young Stellar Object (MYSO): A protostar exceeding ~8 M⊙ that continues to accrete from its natal cloud.

Protocluster: A dense, gravitationally bound region within which multiple protostars form nearly simultaneously.

Maser: Microwave Amplification by Stimulated Emission of Radiation; provides high-precision kinematic tracers of dense gas.

Core fragmentation: The breakup of a collapsing molecular core into multiple bound fragments, leading to stellar multiplicity.

References

1. A probable Keplerian disk feeding an optically revealed massive young star. Nature (2023).
2. Observations of high-order multiplicity in a high-mass stellar protocluster. Nature Astronomy (2024).
3. Detection of a High-velocity Jet from MWC 349A Traced by Hydrogen Recombination Line Maser Emission. The Astrophysical Journal Letters (2023).
4. Discovery of a sub-Keplerian disk with jet around a 20 M⊙ young star. Astronomy & Astrophysics (2019).
5. Massive Outflows Associated with ATLASGAL Clumps. The Astrophysical Journal Supplement Series (2018).